Weighing vehicles and other cargo before loading them onto aircraft in a theater of operations is critical to the deployment of U.S. military forces. Rolling stock and other cargo must be weighed and measured accurately to calculate the center of balance of each item for proper distribution of weight in the aircraft. The weighing and measuring of equipment and cargo are vital to the safety of the aircraft, the crew, and any passengers. Errors can be fatal. In-ground static scales and tape measures are used for weighing and determining center of balance and are available at most air bases in the United States, but not in remote or undeveloped areas.
Military procedure requires all equipment to be weighed before loading, without guesswork or estimates. Each location requires specifically recalculating weight and center of balance, and taking into account the effects of altitude, temperature, runway length, and aircraft type.
U.S. military forces today are deployed globally and rapidly, often in areas with little infrastructure, rarely including an in-ground static weigh scale. For wheeled vehicles, if an in-ground fixed weigh scale is not available, individual wheel-weigh manual portable scales and tape measures are used to weigh military equipment and to determine the center of balance. Individual wheel-weigh scales are placed under each wheel, and all wheels must be on the scales at the same time, to ensure accuracy.
After weighing the individual wheels or wheel sets, the next step is to measure the distance between the axles, calculate the center of balance, the individual axle weights, and the total vehicle weight. The Air Force loadmaster uses the center-of-balance data and total vehicle weight to plan a specific load for each aircraft.
The process is time-consuming, exhausting, and prone to error, especially under adverse weather conditions. Placing the individual wheel-weigh manual portable scales under the wheels of the vehicle also presents a safety hazard. The process requires 6 to 10 soldiers. The data acquired is used by the loadmaster to determine the loading of the aircraft. No Air Force pilot will take off (and should not) without clearance from the loadmaster, who is responsible for aircraft safety with respect to loading.
Currently, Army units use portable individual wheel weight or fixed in-ground static scales, tape measures, and calculators to determine vehicle axle weights, total vehicle and cargo weight and center of balance for vehicles and cargo to be transshipped via railcar, ship, or airlifted in support of military and humanitarian operations. The process of manually weighing and measuring all vehicles and cargo subject to these transshipment operations is time-consuming, labor-intensive, and most importantly is prone to human errors that can result in safety hazards and inaccurate data. The identification, weight and center of balance information on each piece of cargo and vehicle must be manually entered into logistics load planning systems introducing the high likelihood of human key-stroke error into the deployment preparation process. Incorrect information introduced into the Defense Transportation System (DTS) can negatively impact onward movement of cargo and vehicles in theater, needlessly delaying essential supplies and equipment to the end-user/soldier. The importance of having correct, timely information in the DTS for use by all services cannot be overstated. In austere areas of operations, scales may not be available at all, and the vehicle and cargo weight and center of balance must be estimated. This process is even more susceptible to human error. The lack of a standardized airlift-weighing system for joint service use also creates redundant weighing and manual data entry requirements at the cost of scarce resources and time.
The Army identifies the vehicles and manually enters the data into Transportation Coordinators' Automated Information for Movements System II (TC-AIMS II) and then manually calculates vehicle axle weights and balance data and manually records and transfers this data to Automated Air Load Planning System (AALPS) personnel who manually enter it into the AALPS system. Each of these steps in the process is prone to human error. By establishing automated data exchange links between (1) WIM-II and the vehicle RFID tags, and (2) WIM-II device and AALPS, vehicle ID and WIM-II data could be automatically transferred to AALPS, thus eliminating those human errors and at the same time expediting the process.
In the private sector, considerable effort has been made by the federal and state transportation agencies and motor carriers to increase the efficiency of enforcement operations at the highway weigh-stations. For example, operational tests and regional deployments such as Advantage I-75, Heavy Vehicle Electronic License Plate Program (HELP) Crescent project, Prepass and Commercial Vehicle Information Systems and Networks (CVISN) are making great strides towards improving the productivity of both enforcement officers and motor carriers at weigh stations. One of the significant technical advances that have helped lead to these improvements is the development of weigh-in-motion systems. In conjunction with other technologies, weigh-in-motion systems are used to screen out overweight commercial vehicles approaching the weigh stations. Unfortunately, a large majority of carriers are not participating in the programs such as Advantage I-75 and are still required to stop at the weigh-stations. Furthermore, although existing commercially available WIM systems can be use as screening devices they do not provide the accuracy required (<1%) for final certification and ticketing of overweight vehicles. There is considerable room for improvement in accuracy and variability in the commercial WIM systems.
At best, weight enforcement activities are slow and cumbersome causing substantial overcrowding at weigh stations. Law enforcement officials are forced to either create unsafe conditions by allowing vehicles to backup in long lines near the weigh station entrance ramps or allow carriers to bypass weigh stations completely. Each day several thousand carriers travel by various weigh stations. Approximately 70% of these vehicles bypass the weigh stations due to the overcrowded conditions. Traffic simulations of a low-speed WIM system indicate one can reduce the average delay for a motor carrier from 280 seconds to 40 seconds and eliminate vehicles bypassing the weigh station. The successful implementation of converting a static scale to a high-accuracy, low-speed weigh-in-motion system will allow weight enforcement officials to weigh all carriers thus increasing productivity and operational efficiency through increased throughput.
Conventional WIM systems used today are plagued with problems of accuracy. Mainline WIM systems have a typical accuracy error of greater than 5%. This fact limits their utility in enforcement and other applications because users often do not trust the measurements obtained.
It is an object of the present invention to provide a system and method for identifying, validating, weighing and characterizing moving or stationary vehicles and cargo with a weigh-in-motion (WIM) system that is more accurate than the prior art and that can be interfaced with a data management system for load planning, law enforcement, and cargo inspection in both military and commercial applications.